High Octane

Try some of these :
[Alt]+[F1] : Selfdestruct
[Alt]+[F2] : Destroy all enemies
[Alt]+[F3] : Full tank
[Alt]+[F4] : Full ammo
[Alt]+[F5] : Full shield
[Alt]+[F6] : Add one lap
[Alt]+[z] : Autopilot on
[Alt]+[y] : Autopilot on (alternative)
[Alt]+[c] : Autopilot off

On some versions, these keys must be activated as follows:
During play, press [Ctrl]+[Tab].
A puzzle will appear.
Solve it.
Press [Ctrl]+[Tab] again. (Information from Cheat Machine)